The present invention relates to a glass fibre mat. It further relates to products containing glass fibre mats, particularly a CV floor covering comprising a glass fibre mat as a structural layer.
Glass fibre mats are known in multifarious embodiments and for various applications. Also known are customary methods of producing glass fibre mats from glass fibres and binders. A significant application of glass fibre mats is their use as a carrier material in floor coverings, particularly in CV (Cushioned Vinyl) floor coverings. During the production of CV floor coverings, the glass fibre mat is typically initially impregnated in a first step with a PVC paste (particularly Plastisol). For this purpose, the PVC paste is usually applied to the glass fibre mat by means of a coating knife in a predetermined layer thickness or with a predetermined surface weight (e.g. approx. 400 g/m2). A further layer of PVC paste is then applied to the glass fibre mat impregnated in such a way, wherein the surface weight of this second layer can typically lie roughly within the same order of magnitude as the impregnating coating. The back foaming, i.e. the application of an elastically flexible coating to the back side of the glass fibre mat, then takes place. The usable side can then receive a final finishing, for example by means of a coating of clear varnish or other special coatings. This kind of production of CV floor coverings has been known in the PVC industry for some time and is widely used in different variants.
Various requirements are made of the glass fibre mat forming the carrier layer in this respect, some of which are to some extent in conflict with one another. Hence, the glass fibre mat should exhibit good mechanical strength, namely both during the processing and also during the use of the floor covering designed and produced using said glass fibre mat. It is therefore important for both the PVC paste and also the back foaming to create an optimal mechanical connection with the glass fibre mat, so that these layers are prevented from separating from the glass fibre mat when the floor covering is in use. On the other hand, the PVC paste, which is applied to the glass fibre mat by means of a coating knife, as described above, must be prevented from penetrating through said glass fibre mat. This is because otherwise more or less noticeable lumps of PVC form on the back side of the glass fibre mat, where the backing foam is to be applied subsequently, which has a substantially adverse effect on the level of comfort when walking on the CV floor covering. Furthermore, as usual cost considerations play a part, both in relation to the production of the glass fibre mat and also in relation to the impregnation thereof with PVC paste, in which case the consumption of PVC paste for impregnation is crucially dependent on the thickness and the properties (pore volume, permeability, absorbability, pore size distribution) of the glass fibre mat.